Lighting device and method of making lighting device

ABSTRACT

A lighting device comprises a solid state light emitter on a circuit board, and an optic held in place relative to the first circuit board, a voltage drop across the emitter at least 60 volts. A lighting device comprises a solid state light emitter on a first circuit board, an optic held in place relative to the first circuit board, and a non-isolated power supply. A lighting device comprises a solid state light emitter on a first circuit board, and a flame-rated optic held in place relative to the first circuit board. An optic, comprising a translucent region, a first dimension not larger than about 10 mm, a second dimension not larger than 15 mm. A flame-rated optic comprising a translucent region, structure configured to hold the optic in place relative to a circuit board. Methods of making lighting devices.

FIELD OF THE INVENTIVE SUBJECT MATTER

The inventive subject matter relates to the field of generalillumination. In some aspects, the present inventive subject matterrelates to a lighting device that comprises at least a first circuitboard and at least a first solid state light emitter on the firstcircuit board. In some aspects, the present inventive subject matterrelates to a lighting device that comprises one or more solid statelight emitters. In some aspects, the present inventive subject matterrelates to a lighting device that comprises at least a first solid statelight emitter, in which a voltage supplied to the lighting device is atleast 60 volts (and in some aspects, in which a voltage supplied to thelighting device is at least 42.4 volts). In some aspects, the presentinventive subject matter relates to a lighting device that comprises atleast a first solid state light emitter and at least a first powersupply configured to supply power to illuminate the first solid statelight emitter, in which the first power supply is non-isolated. In someaspects, the present inventive subject matter relates to one or morecomponents for use in making a lighting device. In some aspects, thepresent inventive subject matter relates to a method of making alighting device.

BACKGROUND

There is an ongoing effort to develop systems that are moreenergy-efficient. A large proportion (some estimates are as high astwenty-five percent) of the electricity generated in the United Stateseach year goes to lighting, a large portion of which is generalillumination (e.g., downlights, flood lights, spotlights and othergeneral residential or commercial illumination products). Accordingly,there is an ongoing need to provide lighting that is moreenergy-efficient.

Solid state light emitters (e.g., light emitting diodes) are receivingmuch attention due to their energy efficiency. It is well known thatincandescent light bulbs are very energy-inefficient light sources—aboutninety percent of the electricity they consume is released as heatrather than light. Fluorescent light bulbs are more efficient thanincandescent light bulbs (by a factor of about 10) but are still lessefficient than solid state light emitters, such as light emittingdiodes.

In addition, as compared to the normal lifetimes of solid state lightemitters, e.g., light emitting diodes, incandescent light bulbs haverelatively short lifetimes, i.e., typically about 750-1000 hours. Incomparison, light emitting diodes, for example, have typical lifetimesbetween 50,000 and 70,000 hours. Fluorescent bulbs have longer lifetimesthan incandescent lights (e.g., fluorescent bulbs typically havelifetimes of 10,000-20,000 hours), but provide less favorable colorreproduction. The typical lifetime of conventional fixtures is about 20years, corresponding to a light-producing device usage of at least about44,000 hours (based on usage of 6 hours per day for 20 years). Where thelight-producing device lifetime of the light emitter is less than thelifetime of the fixture, the need for periodic change-outs is presented.The impact of the need to replace light emitters is particularlypronounced where access is difficult (e.g., vaulted ceilings, bridges,high buildings, highway tunnels) and/or where change-out costs areextremely high.

LED lighting systems can offer a long operational lifetime relative toconventional incandescent and fluorescent bulbs. LED lighting systemlifetime is typically measured by an “L70 lifetime”, i.e., a number ofoperational hours in which the light output of the LED lighting systemdoes not degrade by more than 30%. Typically, an L70 lifetime of atleast 25,000 hours is desirable, and has become a standard design goal.As used herein, L70 lifetime is defined by Illuminating EngineeringSociety Standard LM-80-08, entitled “IES Approved Method for MeasuringLumen Maintenance of LED Light Sources”, Sep. 22, 2008, ISBN No.978-0-87995-227-3, also referred to herein as “LM-80”, the disclosure ofwhich is hereby incorporated herein by reference in its entirety as ifset forth fully herein.

LEDs also may be energy efficient, so as to satisfy ENERGY STAR® programrequirements. ENERGY STAR program requirements for LEDs are defined in“ENERGY STAR® Program Requirements for Solid State Lighting Luminaires,Eligibility Criteria—Version 1.1”, Final: Dec. 19, 2008, the disclosureof which is hereby incorporated herein by reference in its entirety asif set forth fully herein.

Heat is a major concern in obtaining a desirable operational lifetimefor solid state light emitters. As is well known, an LED also generatesconsiderable heat during the generation of light. The heat is generallymeasured by a “junction temperature”, i.e., the temperature of thesemiconductor junction of the LED. In order to provide an acceptablelifetime, for example, an L70 of at least 25,000 hours, it is desirableto ensure that the junction temperature should not be above 85° C. Inorder to ensure a junction temperature that is not above 85° C., variousheat sinking schemes have been developed to dissipate at least some ofthe heat that is generated by the LED. See, for example, ApplicationNote: CLD-APO6.006, entitled Cree® XLamp® XR Family & 4550 LEDReliability, published at cree.com/xlamp, September 2008.

In order to encourage development and deployment of highly energyefficient solid state lighting (SSL) products to replace several of themost common lighting products currently used in the United States,including 60-Watt A19 incandescent and PAR 38 halogen incandescentlamps, the Bright Tomorrow Lighting Competition (L Prize™) has beenauthorized in the Energy Independence and Security Act of 2007 (EISA).The L Prize is described in “Bright Tomorrow Lighting Competition (LPrize™)”, May 28, 2008, Document No. 08NT006643, the disclosure of whichis hereby incorporated herein by reference in its entirety as if setforth fully herein. The L Prize winner must conform to many productrequirements including light output, wattage, color rendering index,correlated color temperature, expected lifetime, dimensions and basetype.

Although the development of solid state light emitters (e.g., lightemitting diodes) has in many ways revolutionized the lighting industry,some of the characteristics of solid state light emitters have presentedchallenges, some of which have not yet been fully met.

Accordingly, for these and other reasons, efforts have been ongoing todevelop ways by which solid state light emitters, which may or may notinclude luminescent material(s), can be used in place of incandescentlights, fluorescent lights and other light-generating devices in a widevariety of applications. In addition, where light emitting diodes (orother solid state light emitters) are already being used, efforts areongoing to provide solid state light emitters that are improved, e.g.,with respect to energy efficiency, color rendering index (CRI Ra),contrast, efficacy (lm/W), and/or duration of service.

BRIEF SUMMARY

There are two primary types of situations where a lighting device needsto be “flame-rated,” i.e., where it is necessary, in order for thelighting device to be listed under current UL 1598 standards, for thelighting device to have structures and/or mechanisms to preventaccidental contact of a user with the active electrical components andto prevent hot material from escaping the lighting device in the eventof fire. UL 1598 standards are well known to persons of skill in theart, and descriptions of UL 1598 are readily available.

One type of situation where a lighting device needs to be flame-rated(in order to be listed under current UL 1598 standards) is where thelighting device includes a “non-isolated” power supply. Many solid statelight emitters, e.g., light emitting diodes, typically run best on DCcurrent. Line voltage, however, is usually AC. Accordingly, lightingdevices that comprise one or more solid state light emitters typicallyuse power supplies to provide appropriate electrical current to thesolid state light emitter(s). The expression “non-isolated” means thatone or more active electrical input components of the power supplyis/are not isolated from one or more active electrical output componentsof the power supply. Persons of skill in the art are familiar with awide variety of isolated power supplies and a wide variety ofnon-isolated power supplies, and persons of skill in the art are veryfamiliar with, and are readily able to, make, obtain, design andimplement non-isolated power supplies and isolated power supplies, andto distinguish non-isolated power supplies from isolated power supplies.

Another type of situation where a lighting device needs to beflame-rated is where the voltage supplied to the lighting device exceedsa particular maximum value (e.g., in the U.S., if the voltage suppliedto the lighting device exceeds 60 V, an enclosure is required, i.e., thelighting device needs to be flame rated; in Canada, if the voltagesupplied to the lighting device exceeds 42.4 V, an enclosure isrequired). In other words, in order for a lighting device in which avoltage drop across a light emitter (or a combination of light emitters,e.g., a series string of solid state light emitters) is 60 volts or moreto be listed under current UL 1598 standards, it is necessary for thelighting device to be flame-rated.

One requirement that must be met in order for a lighting device to beflame-rated is that (1) a barrier around the lighting device (or eachregion thereof) must be UL 94 5VA rated, or (2) the barrier (or regionsthereof) must be made of a material that is UL 94 V0 rated and thebarrier must pass the UL 94 5VA 5 inch flame test (i.e., in general, thematerial is UL 94 V0 rated and is thick enough to pass the UL 94 5VA 5inch flame test). A statement that a material is “UL 94 5VA rated” meansthat the material passes the UL 94 5VA test. A statement that a barrieris “UL 94 V0 rated” means that the barrier passes the UL 94 V0 test. TheUL 94 5VA test, the UL 94 V0 test, and the UL 94 5VA 5 inch flame testare all well-known to persons of skill in the art, and descriptions ofthese tests are readily available.

Flame-rated lenses generally have higher lumen loss and greater costthan non-flame-rated lenses. For example, in many instances, flame-ratedlenses are made of polycarbonate (PC), which has higher lumen loss andis more expensive than materials (e.g., acrylic such as poly(methylmethacrylate) (i.e., PMMA)) typically used to make non-flame-ratedlenses. With large lenses, the cost implications of using a flame-ratedPC are multiplied. Accordingly, in many instances, efforts are made toavoid the need to use flame-rated lenses.

As noted above, however, there is an ongoing need to provide lightingdevices that are of higher energy efficiency. Better energy efficiencyfor devices which include one or more solid state light emitters (e.g.,one or more LEDs and/or one or more light emitting diode chips) is with“higher voltage, lower current” compared to “lower voltage, highercurrent”.

The improved driver technology at lower drive currents can be viewed asfollows:

a) The associated loss of power with current (at fixed resistance) isequal to the square of the current times the resistance (i.e.,Power=I²R). Hence, a lower current approach will achieve higherefficiencies;

b) the use of higher voltage, lower current can in many cases make itpossible to employ a boost topology (as opposed to, e.g., a bucktopology) for the driver topology (persons of skill in the art arefamiliar with designing circuitry in which there is sufficient voltageheadroom for the use of a boost topology, and such persons are familiarwith the added energy efficiency that can be enjoyed through the use ofa boost driver topology (as opposed to, e.g., a buck driver topoology).

In some aspects of the present inventive subject matter, for the sake ofenergy efficiency gains described above, higher voltage is employed(i.e., one or more high-voltage topology is employed). In some aspectsof the present inventive subject matter, high enough voltage is usedthat a flame-rated enclosure is needed to satisfy UL requirements.

In a first type of high-voltage topology, there is provided a lightemitter which comprises a plurality of light emitting devices which aremechanically interconnected to one another (e.g., on a common substrateon which the devices were formed) and which are electricallyinterconnected in any suitable arrangement (e.g., in series, in an arrayof at least two serially connected subsets of light emitting devices,each subset comprising at least two light emitting devices electricallyconnected in parallel, etc.). A wide variety of high-voltage topologydevices are described in U.S. patent application Ser. No. 12/017,558,filed on Jan. 22, 2008 (now U.S. Patent Publication No. 2008/0179602)(attorney docket number P0940; 931-056 NP), the entirety of which ishereby incorporated by reference as if set forth in its entirety, andother high-voltage topology devices are described in U.S. patentapplication Ser. No. 12/017,600, filed on Jan. 22, 2008 (now U.S. PatentPublication No. 2008/0211416) (attorney docket number P0981; 931-078NP), the entirety of which is hereby incorporated by reference as if setforth in its entirety. In some embodiments, a light emitter can includea plurality of light emitting devices from a contiguous region of awafer of light emitting devices. In some embodiments, a plurality oflight emitting devices can be formed by depositing stacked activelayers, e.g., on a wafer and/or substrate, and then isolating respectiveregions of those stacked layers from each other (i.e., so that therespective regions are not electrically connected with each other) toprovide a plurality of light emitting devices which remain mechanicallyconnected to one another, e.g., by a common wafer and/or substrate. Insuch a case, the light emitting devices may be defined by one or moreinsulating regions that define the peripheries of individual lightemitting devices, and/or by one or more trenches that define theperipheries of the individual light emitting devices, and the isolatedregions of the stacked layers (each of which functions as a separatelight emitting device) can be electrically connected to one another inany suitable arrangement (e.g., in series).

In a second type of high-voltage topology, there is provided a lightemitter which comprises a plurality of small light emitting deviceswhich are electrically connected to one another such that the lightemitter employs high voltage (i.e., at least 60 volts or at least 42.4volts). In a representative example of this type of high-voltagetopology, a single light emitting diode chip (e.g., 1 mm×1 mm) whichruns at about 3 volts can be divided into sixteen smaller light emittingdiode chips (e.g., by cutting in a 4×4 array), and the sixteen smallerchips can then be placed adjacent one another (e.g., in the form of a1.4 mm×1.4 mm light emitter), with the sixteen smaller chips connectedin series, whereby the light emitter runs at about 48 volts.

The use of a high voltage power supply topology makes it possible toemploy smaller, lower cost, and/or more efficient power supplies forsolid state lighting applications. For at least reasons discussed above,sse of a high voltage power supply topology, however, also presentschallenges. Frequently, especially in large area light sources such astroffers, low-voltage class 2 power supplies are used. Using suchlow-voltage power supplies makes it possible for the lenses used inthese troffers to be made from a non-flame rated material. In the caseof a high voltage supply (and corresponding high voltage LEDs), as notedabove, these voltages incur a regulatory requirement to have aflame-rated lens.

In accordance with some aspects of the present inventive subject matter,there is provided an optic that is made from a flame-rated resin andthat is attached to a solid state light emitter circuit board on whichone or more solid state light emitters (e.g., one or more LEDs and/orone or more light emitting diode chips) are provided, and optionally theoptic interfaces to at least one of the one or more solid state lightemitters with one or more index-matching structures. Also, optionally,the flame-rated optic may include one or more refractive elements todirect, collimate or otherwise modify the light distribution from atleast one of the one or more solid state light emitters.

By having the flame-rated material attached to the solid state lightemitter circuit board (and optionally in very close proximity to atleast one of the one or more solid state light emitters), the solidstate light emitter circuit board/optic assembly itself becomes the“light source”, without need for further UL-required flame barriers.Because the area of the solid state light emitter circuit board isusually much smaller than the area of the lenses (e.g., in manyinstances, an LED printed circuit board is between 50% of the lens sizefor downlights and as little as 5% or less in a troffer), the cost ofthe flame-rated material is much lower. Any increased light absorptionin the flame-rated material is still present, but can be mitigated bythe use of an index matching material, e.g., to reduce, minimize oreliminate Fresnel losses that might otherwise occur at the entry surfaceof a flame-rated lens.

In accordance with one aspect of the present inventive subject matter,there is provided a lighting device, comprising:

at least a first circuit board; and

at least a first optic held in place relative to the first circuitboard.

In accordance with another aspect of the present inventive subjectmatter, there is provided a lighting device, comprising:

at least a first solid state light emitter; and

at least a first optic held in place relative to the first solid statelight emitter.

In accordance with a first aspect of the present inventive subjectmatter, there is provided a lighting device, comprising:

at least a first circuit board;

at least a first solid state light emitter on the first circuit board;and

at least a first optic held in place relative to the first circuitboard,

at least part of the first solid state light emitter between at least aportion of the first circuit board and at least a portion of the firstoptic,

if the first solid state light emitter is illuminated, at least aportion of light emitted by the first solid state light emitter passesthrough the first optic, and

a voltage supplied to the lighting device is at least 60 volts (or inanother aspect, at least 42.4 volts), or in other aspects of the presentinventive subject matter, at least 10 volts, at least 20 volts, at least30 volts, at least 40 volts, at least 50 volts, at least 70 volts, atleast 80 volts, 60-200 volts, 70-150 volts, 80-100 volts, 10-250 volts,20-220 volts, 30-200 volts, 40-180 volts, 50-160 volts, 60-150 volts,60-140 volts, 60-130 volts, 60-120 volts, 60-110 volts, 60-100 volts, or60-80 volts.

In accordance with a second aspect of the present inventive subjectmatter, there is provided a lighting device, comprising:

at least a first circuit board;

at least a first solid state light emitter on the first circuit board;

at least a first optic held in place relative to the first circuitboard; and

at least a first non-isolated power supply configured to supply power toilluminate the first solid state light emitter;

at least part of the first solid state light emitter between at least aportion of the first circuit board and at least a portion of the firstoptic, and

if the first solid state light emitter is illuminated, at least aportion of light emitted by the first solid state light emitter passesthrough the first optic.

In accordance with a third aspect of the present inventive subjectmatter, there is provided a lighting device, comprising:

at least a first circuit board;

at least a first solid state light emitter on the first circuit board;and

at least a first optic held in place relative to the first circuitboard,

at least part of the first solid state light emitter between at least aportion of the first circuit board and at least a portion of the firstoptic,

if the first solid state light emitter is illuminated, at least aportion of light emitted by the first solid state light emitter passesthrough the first optic, and

the first optic is flame-rated.

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,the first optic comprises at least a first luminescent material.

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,the lighting device further comprises at least a first index-matchingelement between at least a portion of the first solid state lightemitter and the first optic. In some of such embodiments, which caninclude or not include, as suitable, any of the other features describedherein, the index-matching element comprises at least a firstluminescent material.

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,the first solid state light emitter is an LED.

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,the first solid state light emitter is a light emitting diode chip indirect contact with the first circuit board.

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,the first solid state light emitter comprises a plurality of lightemitting devices formed by depositing stacked active layers on a waferand/or substrate, and then isolating respective regions of those stackedlayers from each other to provide a plurality of light emitting deviceswhich are mechanically connected to one another.

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,the first solid state light emitter comprises a plurality of lightemitting diode chips arranged in series on a first region of the firstcircuit board, the first region having a surface area of not larger thanabout 2.0 square millimeters.

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,at least a first dimension of the lighting device is not larger thanabout 10 mm (and in some embodiments, not larger than about 8 mm; insome embodiments, not larger than about 6 mm; in some embodiments, notlarger than about 4 mm; and in some embodiments, not larger than about 2mm). In some of such embodiments, which can include or not include, assuitable, any of the other features described herein, at least a seconddimension of the lighting device is not larger than about 15 mm (and insome embodiments, not larger than about 10 mm; in some embodiments, notlarger than about 8 mm; and in some embodiments, not larger than about 6mm).

In some embodiments in accordance with any of the first, second andthird aspects of the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,the first optic is in direct contact with the first circuit board.

In some embodiments in accordance with either of the first and secondaspects of the present inventive subject matter, which can include ornot include, as suitable, any of the other features described herein,the first optic is flame-rated.

In some embodiments in accordance with either of the first and thirdaspects of the present inventive subject matter, which can include ornot include, as suitable, any of the other features described herein,the lighting device further comprises at least a first power supply. Insome of such embodiments, which can include or not include, as suitable,any of the other features described herein, the first power supply isnon-isolated.

In accordance with a fourth aspect of the present inventive subjectmatter, there is provided an optic, comprising:

at least a first substantially transparent region,

at least a first dimension of the optic not larger than about 10 mm,

at least a second dimension of the optic not larger than about 15 mm.

In some embodiments in accordance with the fourth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the optic is flame-rated.

In some embodiments in accordance with the fourth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the optic comprises at leastone structure configured to hold the optic in place relative to acircuit board comprising six sides, each side substantially parallel toone other of the sides and substantially perpendicular to four other ofthe sides.

In some embodiments in accordance with the fourth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the optic comprises at leastfirst and second structures configured to hold the optic in placerelative to a circuit board by contacting opposite sides of the circuitboard.

In accordance with a fifth aspect of the present inventive subjectmatter, there is provided an optic, comprising:

at least a first substantially transparent region,

at least one structure configured to hold the optic in place relative toa circuit board,

the optic flame-rated.

In some embodiments in accordance with the fifth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the at least one structureconfigured to hold the optic in place relative to a circuit boardcomprises at least one structure configured to hold the optic in placerelative to a circuit board comprising six sides, each sidesubstantially parallel to one other of the sides and substantiallyperpendicular to four other of the sides.

In some embodiments in accordance with the fifth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the at least one structureconfigured to hold the optic in place relative to a circuit board opticcomprises at least first and second structures configured to hold theoptic in place relative to a circuit board by contacting opposite sidesof the circuit board.

In some embodiments in accordance with either of the fourth and fifthaspects of the present inventive subject matter, which can include ornot include, as suitable, any of the other features described herein,the first optic comprises at least a first luminescent material.

In some embodiments in accordance with either of the fourth and fifthaspects of the present inventive subject matter, which can include ornot include, as suitable, any of the other features described herein,the optic comprises at least one curved region.

In some embodiments in accordance with either of the fourth and fifthaspects of the present inventive subject matter, which can include ornot include, as suitable, any of the other features described herein,the optic comprises at least one curved region on each of two oppositesides.

In accordance with a sixth aspect of the present inventive subjectmatter, there is provided a method of making a lighting device,comprising:

bringing at least a first structure of a first optic into contact with afirst circuit board, the first structure configured to hold the firstoptic in place relative to the first circuit board,

at least a first solid state light emitter on the first circuit board,

so that:

-   -   at least part of the first solid state light emitter is between        at least a portion of the first circuit board and at least a        portion of the first optic, and    -   if the first solid state light emitter is illuminated, at least        a portion of light emitted by the first solid state light        emitter passes through the first optic.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, a voltage of at least 60volts (and in some embodiments, at least 42.4 volts) is supplied to thelighting device.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the method further comprisesplacing at least a first index-matching element so that the firstindex-matching element is between at least a portion of the first solidstate light emitter and the first optic.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the first optic isflame-rated.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the first solid state lightemitter is an LED.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the first solid state lightemitter is a light emitting diode chip in direct contact with the firstcircuit board.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the first solid state lightemitter comprises a plurality of light emitting devices formed bydepositing stacked active layers on a wafer and/or substrate, and thenisolating respective regions of those stacked layers from each other toprovide a plurality of light emitting devices which are mechanicallyconnected to one another.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the first solid state lightemitter comprises a plurality of light emitting diode chips arranged inseries on a first region of the first circuit board, the first regionhaving a surface area of not larger than about 2.0 square millimeters.

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, at least a first dimensionof the optic is not larger than about 10 mm (and in some embodiments,not larger than about 8 mm; in some embodiments, not larger than about 6mm; in some embodiments, not larger than about 4 mm; and in someembodiments, not larger than about 2 mm).

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, at least a second dimensionof the optic is not larger than about 15 mm (and in some embodiments,not larger than about 10 mm; in some embodiments, not larger than about8 mm; and in some embodiments, not larger than about 6 mm).

In some embodiments in accordance with the sixth aspect of the presentinventive subject matter, which can include or not include, as suitable,any of the other features described herein, the method further compriseselectrically connecting at least a first power supply to the firstcircuit board. In some of such embodiments, which can include or notinclude, as suitable, any of the other features described herein, thefirst power supply is non-isolated.

In some embodiments in accordance with the present inventive subjectmatter, one or more features can be provided to self-secure an optic toa circuit board (e.g., an LED printed circuit board). These featuresthemselves can optionally provide mechanical retention and compressionfor thermal benefit within the larger system.

In some embodiments in accordance with the present inventive subjectmatter, one or more of the following can be achieved:

-   -   implementation of a high voltage LED system, enabling smaller,        more efficient and lower cost power supplies, without the        inclusion of large, expensive flame-rated lenses;    -   optionally, mitigation of one interface loss by the use of        index-matching gel between a solid state light emitter and a        primary optic;    -   optionally, elimination of the packaging cost of LEDs and        improved thermal performance (utilizing chip-on-board) without        suffering loss of optical performance associated with LED        packaging;    -   versatility of optical configuration, allowing for multiple        different optical distributions achievable with different        lenses.

The inventive subject matter may be more fully understood with referenceto the accompanying drawings and the following detailed description ofthe inventive subject matter.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a schematic cross-sectional view of a lighting device 10according to the present inventive subject matter.

FIG. 2 is a schematic bottom view of the lighting device 10.

FIG. 3 is a schematic cross-sectional view of a lighting deviceaccording to the present inventive subject matter.

FIG. 4 is a schematic top view of an optic 33 according to the presentinventive subject matter.

FIG. 5 is a schematic top view of a solid state light emitter on acircuit board.

FIG. 6 is a schematic top view of an alternative circuit board 61 onwhich five light emitting diode chips 62 are mounted (chip-on-board).

FIG. 7 is a schematic top view of an alternative optic 71 for use withthe circuit board 61 depicted in FIG. 6.

FIG. 8 is a schematic cross-sectional view of the optic 71, taken alongthe plane 8-8 in FIG. 7.

FIG. 9 is a schematic top view of an alternative optic 91 for use withthe circuit board 61 depicted in FIG. 6.

FIG. 10 is a schematic top view of an alternative circuit board 101 onwhich sixteen light emitting diode chips 102 are mounted(chip-on-board).

FIG. 11 is a schematic top view of an alternative optic 111 for use withthe circuit board 101 depicted in FIG. 10.

FIG. 12 is a schematic top view of an alternative circuit board 121 onwhich sixteen light emitting diode chips 122 are mounted(chip-on-board).

FIG. 13 is a schematic top view of an alternative optic 131 for use withthe circuit board 121 depicted in FIG. 12.

FIG. 14 is a schematic cross-sectional view of the optic 131 along plane14-14.

FIG. 15 is a top plan view of a high voltage monolithic light emitter150 that can be employed in some embodiments in accordance with thepresent inventive subject matter.

FIG. 16 is an exemplary cross-sectional illustration of the monolithiclight emitter 150 taken along plane 15-15.

FIG. 17 is a schematic top view of an alternative optic 171 for use withthe circuit board 61 depicted in FIG. 6.

FIG. 18 is a schematic cross-sectional view of the optic 171, takenalong the plane 18-18 in FIG. 17.

FIG. 19 is a top plan view of a high voltage light emitter 190 that canbe employed in some embodiments in accordance with the present inventivesubject matter.

FIG. 20 is a schematic sectional view of a lamp 200 that comprises acircuit board 201, a solid state light emitter 202 on the circuit board201, an optic 203, a housing 204 and a diffuser 205.

FIG. 21 is a schematic perspective view of a lamp 210 in the form of alinear troffer, comprising a lighting device 211 (which comprises acircuit board with ten light emitting diode chips mounted thereon in aline, and a corresponding optic) and a reflective housing 212.

DETAILED DESCRIPTION

The present inventive subject matter now will be described more fullyhereinafter with reference to the accompanying drawings, in whichembodiments of the inventive subject matter are shown. However, thisinventive subject matter should not be construed as being limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the inventive subject matter to those skilled in theart. Like numbers refer to like elements throughout.

As used herein the term “and/or” includes any and all combinations ofone or more of the associated listed items.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the inventivesubject matter. As used herein, the singular forms “a”, “an” and “the”are intended to include the plural forms as well, unless the contextclearly indicates otherwise. It will be further understood that theterms “comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof.

When an element such as a layer, region or structure is referred toherein as being “on”, being mounted “on”, being mounted “to”, orextending “onto” another element, it can be in or on the other element,and/or it can be directly on the other element, and/or it can extenddirectly onto the other element, and it can be in direct contact orindirect contact with the other element (e.g., intervening elements mayalso be present). In contrast, when an element is referred to herein asbeing “directly on” or extending “directly onto” another element, thereare no intervening elements present. Also, when an element is referredto herein as being “attached”, “connected” or “coupled” to anotherelement, it can be directly attached, connected or coupled to the otherelement, or intervening elements may be present. In contrast, when anelement is referred to herein as being “directly attached”, “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. In addition, a statement that a firstelement is “on” a second element is synonymous with a statement that thesecond element is “on” the first element.

The expression “in contact with”, as used herein, means that the firststructure that is in contact with a second structure is in directcontact with the second structure or is in indirect contact with thesecond structure. The expression “in indirect contact with” means thatthe first structure is not in direct contact with the second structure,but that there are a plurality of structures (including the first andsecond structures), and each of the plurality of structures is in directcontact with at least one other of the plurality of structures (e.g.,the first and second structures are in a stack and are separated by oneor more intervening layers). The expression “direct contact”, as used inthe present specification, means that the first structure which is “indirect contact” with a second structure is touching the second structureand there are no intervening structures between the first and secondstructures at least at some location.

A statement herein that two components in a device are “electricallyconnected,” means that there are no components electrically between thecomponents that affect the function or functions provided by the device.For example, two components can be referred to as being electricallyconnected, even though they may have a small resistor between them whichdoes not materially affect the function or functions provided by thedevice (indeed, a wire connecting two components can be thought of as asmall resistor); likewise, two components can be referred to as beingelectrically connected, even though they may have an additionalelectrical component between them which allows the device to perform anadditional function, while not materially affecting the function orfunctions provided by a device which is identical except for notincluding the additional component; similarly, two components which aredirectly connected to each other, or which are directly connected toopposite ends of a wire or a trace on a circuit board, are electricallyconnected. A statement herein that two components in a device are“electrically connected” is distinguishable from a statement that thetwo components are “directly electrically connected”, which means thatthere are no components electrically between the two components.

Although the terms “first”, “second”, etc. may be used herein todescribe various elements, components, regions, layers, sections and/orparameters, these elements, components, regions, layers, sections and/orparameters should not be limited by these terms. These terms are onlyused to distinguish one element, component, region, layer or sectionfrom another region, layer or section. Thus, a first element, component,region, layer or section discussed below could be termed a secondelement, component, region, layer or section without departing from theteachings of the present inventive subject matter.

Relative terms, such as “bottom”, “top”, “horizontal” or “vertical” maybe used herein to describe one element's relationship to another element(or to other elements) as illustrated in the Figures. Such relativeterms are intended to encompass different orientations of the device inaddition to the orientation depicted in the Figures. For example, if thedevice in the Figures is turned over, elements described as being on the“bottom” side would then be oriented on “top” side.

The expression “illumination” (or “illuminated”), as used herein whenreferring to a light emitter, means that at least some current is beingsupplied to the light emitter to cause the light emitter to emit atleast some electromagnetic radiation (e.g., visible light). Theexpression “illuminated” encompasses situations where the light emitteremits electromagnetic radiation continuously, or intermittently at arate such that a human eye would perceive it as emitting electromagneticradiation continuously or intermittently, or where a plurality of lightemitters of the same color or different colors are emittingelectromagnetic radiation intermittently and/or alternatingly (with orwithout overlap in “on” times), e.g., in such a way that a human eyewould perceive them as emitting light continuously or intermittently(and, in some cases where different colors are emitted, as separatecolors or as a mixture of those colors).

The expression “excited”, as used herein when referring to luminescentmaterial, means that at least some electromagnetic radiation (e.g.,visible light, UV light or infrared light) is contacting the luminescentmaterial, causing the luminescent material to emit at least some light.The expression “excited” encompasses situations where the luminescentmaterial emits light continuously, or intermittently at a rate such thata human eye would perceive it as emitting light continuously orintermittently, or where a plurality of luminescent materials that emitlight of the same color or different colors are emitting lightintermittently and/or alternatingly (with or without overlap in “on”times) in such a way that a human eye would perceive them as emittinglight continuously or intermittently (and, in some cases where differentcolors are emitted, as a mixture of those colors).

The expression “lighting device”, as used herein, is not limited, exceptthat it indicates that the device is capable of emitting light. That is,a lighting device can be a device which illuminates an area or volume,e.g., a structure, a swimming pool or spa, a room, a warehouse, anindicator, a road, a parking lot, a vehicle, signage, e.g., road signs,a billboard, a ship, a toy, a mirror, a vessel, an electronic device, aboat, an aircraft, a stadium, a computer, a remote audio device, aremote video device, a cell phone, a tree, a window, an LCD display, acave, a tunnel, a yard, a lamppost, or a device or array of devices thatilluminate an enclosure, or a device that is used for edge orback-lighting (e.g., back light poster, signage, LCD displays), bulbreplacements (e.g., for replacing AC incandescent lights, low voltagelights, fluorescent lights, etc.), lights used for outdoor lighting,lights used for security lighting, lights used for exterior residentiallighting (wall mounts, post/column mounts), ceiling fixtures/wallsconces, under cabinet lighting, lamps (floor and/or table and/or desk),landscape lighting, track lighting, task lighting, specialty lighting,ceiling fan lighting, archival/art display lighting, highvibration/impact lighting, work lights, etc., mirrors/vanity lighting,or any other light emitting device.

The present inventive subject matter further relates to an illuminatedenclosure (the volume of which can be illuminated uniformly ornon-uniformly), comprising an enclosed space and at least one lightingdevice according to the present inventive subject matter, wherein thelighting device illuminates at least a portion of the enclosed space(uniformly or non-uniformly).

The present inventive subject matter is further directed to anilluminated area, comprising at least one item, e.g., selected fromamong the group consisting of a structure, a swimming pool or spa, aroom, a warehouse, an indicator, a road, a parking lot, a vehicle,signage, e.g., road signs, a billboard, a ship, a toy, a mirror, avessel, an electronic device, a boat, an aircraft, a stadium, acomputer, a remote audio device, a remote video device, a cell phone, atree, a window, an LCD display, a cave, a tunnel, a yard, a lamppost,etc., having mounted therein or thereon at least one lighting device asdescribed herein.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive subject matterbelongs. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand the present disclosure and will not be interpreted in an idealizedor overly formal sense unless expressly so defined herein. It will alsobe appreciated by those of skill in the art that references to astructure or feature that is disposed “adjacent” another feature mayhave portions that overlap or underlie the adjacent feature.

As noted above, in accordance with aspects of the present inventivesubject matter, there is provided a lighting device that comprises atleast a first circuit board, at least a first solid state light emitterand at least a first optic held in place relative to the first circuitboard.

The one or more circuit board in lighting devices in accordance with thepresent inventive subject matter can generally be any suitable circuitboard, a wide variety of which are well known and readily available topersons of skill in the art. Representative examples of suitable circuitboards include metal core printed circuit boards (MCPCB's), FR4 circuitboards and flexible circuit boards (e.g., “flex circuit boards”).

The circuit board (or any of the one or more circuit boards) can havefeatures that assist in transferring heat away from the one or moresolid state light emitters and/or that assist in dissipating heatgenerated by the one or more solid state light emitters. For example,persons of skill in the art are familiar with a wide variety of featuresthat can be provided in circuit boards for assisting with heat transferand/or heat dissipation (e.g., the provision of thermal vias, and/or theinclusion of a metal core in a metal core printed circuit board), andany of such features (or any combination of such features) can beincluded, as desired, in any circuit board provided in lighting devicesin accordance with the present inventive subject matter.

Any suitable solid state light emitter (or solid state light emitters)can be employed in the lighting devices according to the presentinventive subject matter. Persons of skill in the art are familiar with,and have ready access to, a wide variety of solid state light emitters.Representative examples of solid state light emitters include lightemitting diodes (inorganic or organic, including polymer light emittingdiodes (PLEDs)) and a wide variety of luminescent materials as well ascombinations (e.g., one or more light emitting diodes and/or one or moreluminescent materials).

A light emitting diode (if included in a lighting device in accordancewith the present inventive subject matter) can be in any suitable form,e.g., a light emitting diode can be provided as an LED (e.g., a packagedLED) on a substrate (which in turn is on a circuit board), a lightemitting diode can be provided as a light emitting diode chip on asubstrate (which in turn is on a circuit board), or a light emittingdiode can be provided as a light emitting diode chip on a circuit board(i.e., chip-on-board), each of which are well known to persons of skillin the art. A solid state light emitter can comprise a lateral device(e.g., a lateral chip), i.e., a device in which both electrical contactsare on one side of the device or a vertical device (e.g., a verticalchip), i.e., a device in which electrical contacts are on opposite sidesof the device, or electrical contacts can be in any suitablearrangement. Electricity can be supplied to a solid state light emitterin any suitable way, e.g., using contacts, wire bonds, etc.

In some embodiments in accordance with the present inventive subjectmatter, once the steps have been taken to include an index-matchingmaterial and utilize a flame-rated lens as a primary optic, employing achip-on-board solution can eliminate substrate cost and molding cost onthe one or more solid state light emitters (e.g., individual LEDs), andcan remove a thermal interface between the LED chip and the outsideenvironment. Thus, a low cost, high thermal and optical performancemethod of implementing high voltage power supplies and LEDs into ageneral illumination system can be obtained.

As noted above, in some embodiments in accordance with the presentinventive subject matter, a solid state light emitter can comprise aplurality of light emitting devices formed by depositing stacked activelayers on a wafer and/or substrate, and then isolating respectiveregions of those stacked layers from each other to provide a pluralityof light emitting devices which are mechanically connected to oneanother. In some of such embodiments, the solid state light emitter canhave a voltage drop of at least 60 volts (in some embodiments, a voltagedrop of at least 42.4 volts), and/or the voltage supplied to thelighting device in which the light emitter is included can be at least60 volts (or at least 42.4 volts).

The solid state light emitters) in any lighting device according to thepresent inventive subject matter can be of any suitable size (or sizes),e.g., and any quantity (or respective quantities) of solid state lightemitters of one or more sizes can be employed. In some instances, forexample, a greater quantity of smaller solid state light emitters can besubstituted for a smaller quantity of larger solid state light emitters,or vice-versa.

Light emitting diodes are semiconductor devices that convert electricalcurrent into light. A wide variety of light emitting diodes are used inincreasingly diverse fields for an ever-expanding range of purposes.More specifically, light emitting diodes are semiconducting devices thatemit light (ultraviolet, visible, or infrared) when a potentialdifference is applied across a p-n junction structure. There are anumber of well known ways to make light emitting diodes and manyassociated structures, and the present inventive subject matter canemploy any such devices.

A light emitting diode produces light by exciting electrons across theband gap between a conduction band and a valence band of a semiconductoractive (light-emitting) layer. The electron transition generates lightat a wavelength that depends on the band gap. Thus, the color of thelight (wavelength) and/or the type of electromagnetic radiation (e.g.,infrared light, visible light, ultraviolet light, near ultravioletlight, etc., and any combinations thereof) emitted by a light emittingdiode depends on the semiconductor materials of the active layers of thelight emitting diode.

The expression “light emitting diode” is used herein to refer to thebasic semiconductor diode structure (i.e., the chip). The commonlyrecognized and commercially available “LED” that is sold (for example)in electronics stores typically represents a “packaged” device made upof a number of parts. These packaged devices typically include asemiconductor based light emitting diode such as (but not limited to)those described in U.S. Pat. Nos. 4,918,487; 5,631,190; and 5,912,477;various wire connections, and a package that encapsulates the lightemitting diode.

A luminescent material is a material that emits a responsive radiation(e.g., visible light) when excited by a source of exciting radiation. Inmany instances, the responsive radiation has a wavelength (or hue) thatis different from the wavelength (or hue) of the exciting radiation.

Luminescent materials can be categorized as being down-converting, i.e.,a material that converts photons to a lower energy level (longerwavelength) or up-converting, i.e., a material that converts photons toa higher energy level (shorter wavelength).

Persons of skill in the art are familiar with, and have ready access to,a variety of luminescent materials that emit light having a desired peakemission wavelength and/or dominant emission wavelength, or a desiredhue, and any of such luminescent materials, or any combinations of suchluminescent materials, can be employed, if desired. One type ofluminescent material are phosphors, which are readily available and wellknown to persons of skill in the art. Other examples of luminescentmaterials include scintillators, day glow tapes and inks that glow inthe visible spectrum upon illumination with ultraviolet light.

One non-limiting representative example of a luminescent material thatcan be employed in the present inventive subject matter is cerium-dopedyttrium aluminum garnet (aka “YAG:Ce” or “YAG”). Another non-limitingrepresentative example of a luminescent material that can be employed inthe present inventive subject matter is CaAlSiN:Eu2+ (aka “CASN” or“BR01”), and a further example of a type of luminescent material isBOSE.

The one or more luminescent materials can be provided in any suitableform. For example, the luminescent element can be embedded in a resin(i.e., a polymeric matrix), such as a silicone material, an epoxymaterial, a glass material or a metal oxide material, and/or can beapplied to one or more surfaces of a resin, to provide a lumiphor.

The solid state light emitter (or solid state light emitters) can bearranged in any suitable way. Persons of skill in the art will readilyidentify a large number of different possible arrangements, any of which(or any combination of which) can be employed in the lighting devicesaccording to the present inventive subject matter.

The solid state light emitter (or the solid state light emitters) can bepositioned in any suitable way. In some embodiments, for example, thesolid state light emitter (or the solid state light emitters), or someof two or more solid state light emitters, can be on one or more circuitboards (which can be positioned in any suitable way).

One or more solid state light emitters can be positioned, attachedand/or mounted in any suitable way, e.g., by using chip on heat sinkmounting techniques, by soldering (e.g., if a solid state light emitteris mounted on a metal core printed circuit board (MCPCB), flex circuitor even a standard PCB, such as an FR4 board with thermal vias), forexample, solid state light emitters can be mounted using substratetechniques such as from Thermastrate Ltd of Northumberland, UK. Ifdesired, a surface of a structure on which the solid state light emitteris mounted, attached or positioned, and/or the one or more solid statelight emitters can be machined or otherwise formed to be of matchingtopography so as to provide high heat sink surface area.

The one or more optic in lighting devices in accordance with the presentinventive subject matter can generally be made of any suitable material,and can be in any suitable shape. Persons of skill in the art arefamiliar with a large number of materials (and combinations ofmaterials) that can be used to make optics for use in making enclosures(or components thereof) that are flame-rated or that are notflame-rated. For example, persons of skill in the art are familiar witha variety of polycarbonate materials which are UL 94 V0 rated and whichcan be used to make light passing structures which are substantiallytransparent and which pass the UL 94 5VA 5 inch flame test (forinstance, such materials are available from Bayer MaterialScience,Teijin Chemicals Ltd., Kingfa Science and Technology Co., Ltd. and E.I.DuPont.de Nemours & Co., to name a few). Persons of skill in the art arealso familiar with a variety of PMMA materials which are not UL 94 WOrated, and which can be used in making enclosures that are notflame-rated.

Persons of skill in the art are familiar with an enormous range ofoptical structures and optical features that can be provided in anoptic, and any of such optical structures and optical features (andcombinations thereof) can be provided in optics for lighting devices inaccordance with the present inventive subject matter.

As used herein, the expression “optical feature” refers to a threedimensional shape that has a contour that differs from the contour ofthe immediate surroundings, or to a pattern of shapes that has a contourthat differs from the contour of the immediate surrounding. The size ofsuch contour can be nano, micro, or macro in size or scale. A pattern ofoptical features can be any suitable pattern for providing a desireddiffusion and/or mixing of light. The pattern can be repeating,pseudo-random or random. The expression “pseudo-random” means a patternthat includes one or more types of random sub-patterns which arerepeated. The expression “random” means a pattern that does not includeany substantial regions which are repeated. Persons of skill in the artare familiar with a wide variety of optical features as defined herein,and any such optical features can be employed in the lighting devicesaccording to the present inventive subject matter.

In some embodiments, at least a portion of the optic (or one or more ofplural optics) is substantially transparent. The expression“substantially transparent”, as used herein, means that the structure(or portion thereof) that is characterized as being substantiallytransparent ultimately (i.e., light that is internally reflected one ormore times and that eventually exits is considered to have passedthrough the optic, even if it exits to the same side of the optic thatit entered) allows passage of at least 90% of incident visible light.

The optic (or one or more of plural optics, if provided) can be held inplace (permanently or removably) relative to a circuit board in anysuitable way. For example, one suitable way for an optic to be held inplace relative to a circuit board is by providing on the optic a region(e.g., a post) that is configured to be pushed through an aperture inthe circuit board and then shaped (e.g., using heat so that it becomesat least soft enough to be mushroomed) so that it cannot be retractedback through the aperture. Another suitable way for an optic to be heldin place relative to a circuit board is by using flexible structuresthat comprise regions (1) which can be moved by force (e.g, by bendingthe flexible structures) to allow a circuit board to be inserted betweenthe flexible structures, and (2) which hold the circuit board in placerelative to the optic which the force is removed. In other embodiments,for example, an optic can be held in place relative to a circuit board(1) by providing threads on an internal surface of a raised edge aroundthe perimeter of the optic which can be threadedly engaged incorresponding threads provided in an edge surface of the circuit board,(2) by providing threads on an edge surface of the optic which can bethreadedly engaged in corresponding threads provided in an internalsurface of a raised edge surface of the circuit board, (3) by providinga clip (or clips) on the optic which engage the circuit board, (4) byproviding a clip (or clips) on the circuit board which engage the optic,(5) by providing a pin (or pins) on the optic which fits into a recess(or recesses) provided on the circuit board, (6) by providing a pin (orpins) on the circuit board which fits into a recess (or recesses)provided on the optic, (7) using screws, bolts, rivets, etc. that extendthrough at least a portion of the optic and at least a portion of thecircuit board, (8) using adhesive, (9) through geometry (e.g., anexternal frustoconical surface on the circuit board engages an internalfrustoconical surface on the optic, (10) by press fitting at least aportion of the circuit board in a recess in the optic, (11) by pressfitting at least a portion of the optic in a recess in the circuitboard, (12) by a ridge and groove (e.g., a ridge on an edge of thecircuit board that fits into a groove or a recess in the optic, or aridge on an edge of a recess in the optic that fits into a groove on thecircuit board), (13) by an arrangement in which a tab on one elementfits into a slot on the other element and optionally the elements arethen moved relative to one another (e.g., one element is slid or rotatedrelative to the other), (14) by compression (e.g., by heating the opticand inserting the circuit board into a recess (in which the circuitboard fits snugly) in the optic, so that when the optic cools down, thecircuit board will be compressed within the recess) etc.

As noted above, in some embodiments in accordance with the presentinventive subject matter, one or more luminescent materials can beprovided in and/or on the optic (or on one or more optic), e.g., aluminescent material can be dispersed within at least a first region ofan optic.

In making lighting devices in accordance with the present inventivesubject matter, large areas of structures can be made, which can laterbe broken into component pieces, if desired. For example, it would bepossible to make a ten-by-ten array of solid state light emitters and/ora corresponding optic, and then break the array and/or the optic intoten strips (each with ten solid state light emitters). In instanceswhere such a capability is desired, features, e.g., perforations, can beprovided to facilitate such breakage.

In some instances, contacts can be provided on any of the structuresdescribed herein (e.g., on sides of circuit boards) in order tofacilitate electrical connection to one or more other structures.

As noted above, in some embodiments in accordance with the presentinventive subject matter, a lighting device can further comprise atleast a first index-matching element between at least a portion of afirst solid state light emitter and a first optic. In general, anindex-matching element (or at least a portion thereof) should have anindex of refraction of a value that is between the value for the indexof refraction of the first solid state light emitter and the value forthe index of refraction of the first optic. Persons of skill in the artare familiar with a wide variety of materials that can be used to makeindex-matching elements of specific index of refraction values (and thatare substantially transparent). An index-matching element can comprisesolid material, liquid material, gel, gaseous material and/or plasmamaterial.

An index-matching element, when included, can be of generally anysuitable shape. In some embodiments, an index-matching elementsubstantially fills a space between a first solid state light emitterand a first optic, i.e., a first region of the index-matching elementcan be in direct contact with the first solid state light emitter and asecond region of the index-matching element can be in direct contactwith the first optic.

In some embodiments in accordance with the present inventive subjectmatter, an index-matching element is provided (or a plurality ofindex-matching elements are provided), and the index-matching element(or one of more of the index-matching elements) comprises one or moreluminescent materials, e.g., a luminescent material can be dispersedwithin at least a first region of an index-matching element. In some ofsuch embodiments, which can include or not include, as suitable, any ofthe other features described herein, the index-matching elementcomprises at least a first luminescent material.

As noted above, in some embodiments in accordance with the presentinventive subject matter, a lighting device can comprise at least onepower supply, which can be isolated or which can be non-isolated. Apower supply (if included) in a lighting device in accordance with thepresent inventive subject matter can comprise any electronic componentsthat are suitable for a lighting device, for example, any of (1) one ormore electrical components employed in converting electrical power(e.g., from AC to DC and/or from one voltage to another voltage), (2)one or more electronic components employed in driving one or more lightemitter, e.g., running one or more light emitter intermittently and/oradjusting the current supplied to one or more light emitters in responseto a user command, a detected change in intensity or color of lightoutput, a detected change in an ambient characteristic such astemperature or background light, etc., and/or a signal contained in theinput power (e.g., a dimming signal in AC power supplied to the lightingdevice), etc., (3) one or more circuit boards (e.g., a metal corecircuit board) for supporting and/or providing current to any electricalcomponents, and/or (4) one or more wires connecting any components(e.g., connecting an Edison socket to a circuit board), etc., e.g.electronic components such as linear current regulated supplies, pulsewidth modulated current and/or voltage regulated supplies, bridgerectifiers, transformers, power factor controllers etc. A power supply(if included) can comprise any suitable circuitry configuration, e.g., aboost configuration and/or a buck configuration, persons of skill in theart being very familiar with a wide variety of such configurations andreadily being able to assemble such configurations.

In some embodiments in accordance with the present inventive subjectmatter, which can include or not include, as suitable, any of the otherfeatures described herein, the lighting device can further comprise ahousing. The housing (if included) can generally be of any suitableshape and size, and can be made out of any suitable material ormaterials. Representative examples of materials that can be used inmaking a housing include, among a wide variety of other materials,extruded aluminum, powder metallurgy formed aluminum, die cast aluminum,liquid crystal polymer, polyphenylene sulfide (PPS), thermoset bulkmolded compound or other composite material. In some embodiments inaccordance with the present inventive subject matter, which can includeor not include, as suitable, any of the other features described herein,a housing (if included) can comprise a material that can be moldedand/or shaped, and/or it can comprise a material that is an effectiveheat sink (i.e., which has high thermal conductivity and/or high heatcapacity).

In some aspects of the present inventive subject matter, which caninclude or not include any of the features described elsewhere herein,there are provided lighting devices that provide good heat dissipation(e.g., in some embodiments, sufficient that one or more solid statelight emitter in the lighting device can continue to provide at least70% of its initial wall plug efficiency for at least 25,000 hours ofoperation of the lighting device, and in some cases for at least 35,000hours or 50,000 hours of operation of the lighting device).

In some embodiments in accordance with the present inventive subjectmatter, there can be provided one or more heat dissipation elements. Aheat dissipation element, if employed, can be made of any suitablematerial, and can be of any suitable shape. In some embodiments, a heattransfer element has high thermal conductivity characteristics, e.g., ithas a thermal conductivity of at least 1 W/m-K. Representative examplesof materials that are suitable for making a heat transfer elementinclude, among a wide variety of other materials, extruded aluminum,powder metallurgy formed aluminum, die cast aluminum, liquid crystalpolymer, polyphenylene sulfide (PPS), thermoset bulk molded compound orother composite material. For example, some embodiments in accordancewith the present inventive subject matter comprise a lighting devicethat comprises one or more solid state light emitters on a circuitboard, the circuit board in turn on a housing made of a material thathas high thermal conductivity (e.g., comprising aluminum, metal alloys,ceramics, polymers mixed with ceramic or metal or metalloid particles,etc.) and that can comprise one or more heat dissipation structures,e.g., fins, heat pipes. Heat transfer from one structure or region of alighting device to another can be enhanced (i.e., thermal resistivitycan be reduced or minimized) using any suitable material or structurefor doing so, a variety of which are known to persons of skill in theart, e.g., by means of chemical or physical bonding and/or byinterposing a heat transfer aid such as a thermal pad, thermal grease,graphite sheets, heat spreaders, thermal transfer regions (e.g.,comprising metals, diamond, DLC), etc.

Some embodiments of lighting devices according to the present inventivesubject matter have passive cooling, and some embodiments of lightingdevices according to the present inventive subject matter have activecooling as well as passive cooling. The expression “active cooling” isused herein in a manner that is consistent with its common usage torefer to cooling that is achieved through the use of some form ofenergy, as opposed to “passive cooling”, which is achieved without theuse of energy (i.e., while energy is supplied to the one or more solidstate light emitters, passive cooling is the cooling that would beachieved without the use of any component(s) that would requireadditional energy in order to function to provide additional cooling).

One or more structures in some embodiments of lighting devices inaccordance with the present inventive subject matter can comprise anysuitable texturing, e.g., ridges, valleys, roughened regions, nodules,protrusions, indentations, etc., e.g., to increase the surface area ofheat dissipation.

Some embodiments of lighting devices in accordance with the presentinventive subject matter (which can include or not include any of thefeatures described elsewhere herein) can include one or more lenses,diffusers or light control elements. Persons of skill in the art arefamiliar with a wide variety of lenses, diffusers and light controlelements, can readily envision a variety of materials out of which alens, a diffuser, or a light control element can be made (e.g.,polycarbonate materials, acrylic materials, fused silica, polystyrene,etc.), and are familiar with and/or can envision a wide variety ofshapes that lenses, diffusers and light control elements can be. Any ofsuch materials and/or shapes can be employed in a lens and/or a diffuserand/or a light control element in an embodiment that includes a lensand/or a diffuser and/or a light control element. As will be understoodby persons skilled in the art, a lens or a diffuser or a light controlelement in a lighting device according to the present inventive subjectmatter can be selected to have any desired effect on incident light (orno effect), such as focusing, diffusing, etc. Any such lens and/ordiffuser and/or light control element can comprise one or moreluminescent materials, e.g., one or more phosphor.

In embodiments in accordance with the present inventive subject matterthat include a lens (or plural lenses), a diffuser (or plural diffusers)and/or a light control element (or plural light control elements), thelens (or lenses), diffuser (or diffusers) and/or light control element(or light control elements) can be positioned in any suitable locationand orientation.

In some embodiments according to the present inventive subject matter,solid state light emitters are electrically with enough solid statelight emitters (or devices) arranged in series to match (or to comeclose to matching) the voltage supplied from to the solid state lightemitters (e.g., in some embodiments, the DC voltage obtained byrectifying line AC current and supplying it to the solid state lightemitters via a power supply). For instance, in some embodiments,sixty-eight solid state light emitters and/or devices (or other numbers,as needed to match the line voltage) (and any of the sixty-eight solidstate light emitters can comprise a number of light emitters and/ordevices arranged in parallel) can be arranged in series, so that thevoltage drop across the entire series is about 162 volts. Providing suchmatching can help provide power supply efficiencies and thereby boostthe overall efficiency of the lighting device. In such lighting devices,total lumen output can be regulated by adjusting the current supplied tothe series of solid state light emitters.

Some embodiments in accordance with the present inventive subject mattercan comprise a power line that can be connected to a source of power(such as a branch circuit, an electrical outlet, a battery, aphotovoltaic collector, etc.) and that can supply power to a lightingdevice. Persons of skill in the art are familiar with, and have readyaccess to, a variety of structures that can be used as a power line. Apower line can be any structure that can carry electrical energy andsupply it to a lighting device according to the present inventivesubject matter.

A lighting device in accordance with the present inventive subjectmatter can comprise an electrical connector. An electrical connector, ifincluded, can be attached to one or more other components of thelighting device in any suitable way, e.g., by screw-threading intoanother component (e.g., a housing member, if included, or a lens, ifincluded), with screws (or bolts or rivets), with clips, with adhesive(e.g., thermal paste), by compression, by press fitting, by a ridge andgroove, or by an arrangement in which a tab on one element fits into aslot on the other element and then the elements are moved relative toone another (e.g., one element is slid or rotated relative to theother).

Various types of electrical connectors are well known to those skilledin the art, and any of such electrical connectors can be attached within(or attached to) the lighting devices according to the present inventivesubject matter. Representative examples of suitable types of electricalconnectors include wires (for splicing to a branch circuit), Edisonplugs (which are receivable in Edison sockets) and GU24 pins (which arereceivable in GU24 sockets). Other well known types of electricalconnectors include 2-pin (round) GX5.3, can DC bay, 2-pin GY6.35,recessed single contact R7s, screw terminals, 4 inch leads, 1 inchribbon leads, 6 inch flex leads, 2-pin GU4, 2-pin GU5.3, 2-pin G4, turn& lock GU7, GU10, G8, G9, 2-pin Pf, min screw E10, DC bay BA15d, mincand E11, med screw E26, mog screw E39, mogul bipost G38, ext. mog endpr GX16d, mod end pr GX16d and med skirted E26/50x39 (seehttps://www.gecatalogs.com/lighting/software/GELightingCatalogSetup.exe).

In some embodiments, drive circuitry can be provided to achieve somedegree of power factor correction. Persons of skill in the art arefamiliar with a variety of power factor controllers (PFCs), and any ofsuch power factor controllers can be employed, if desired, in thelighting devices in accordance with the present inventive subjectmatter. In some embodiments, there can be provided a lighting devicethat may have a power factor of greater than 0.7 and in some embodimentsa power factor of greater than 0.9. In some embodiments, a lightingdevice can have a power factor of greater than 0.5. Such embodiments maynot require power factor correction and, therefore, may be less costlyand smaller in size. Additionally, drive circuitry may be provided fordimming a lighting device.

Energy can be supplied to a lighting device in accordance with thepresent inventive subject matter from any source or combination ofsources, for example, the grid (e.g., line voltage), one or morebatteries, one or more photovoltaic energy collection devices (i.e., adevice that includes one or more photovoltaic cells that convert energyfrom the sun into electrical energy), one or more windmills, etc.

In some embodiments according to the present inventive subject matter,including some embodiments that include or do not include any of thefeatures as discussed herein, the lighting device has a wall plugefficiency of at least 25 lumens per watt, in some cases at least 35lumens per watt, in some cases at least 50 lumens per watt, in somecases at least 60 lumens per watt, in some cases at least 70 lumens perwatt, and in some cases at least 80 lumens per watt.

The expression “wall plug efficiency”, as used herein, is measured inlumens per watt, and means lumens exiting a lighting device, divided byall energy supplied to create the light, as opposed to values forindividual components and/or assemblies of components. Accordingly, wallplug efficiency, as used herein, accounts for all losses, including,among others, any quantum losses, i.e., losses generated in convertingline voltage into current supplied to light emitters, the ratio of thenumber of photons emitted by luminescent material(s) divided by thenumber of photons absorbed by the luminescent material(s), any Stokeslosses, i.e., losses due to the change in frequency involved in theabsorption of light and the re-emission of visible light (e.g., byluminescent material(s)), and any optical losses involved in the lightemitted by a component of the lighting device actually exiting thelighting device. In some embodiments, the lighting devices in accordancewith the present inventive subject matter provide the wall plugefficiencies specified herein when they are supplied with AC power(i.e., where the AC power is converted to DC power before being suppliedto some or all components, the lighting device also experiences lossesfrom such conversion), e.g., AC line voltage. The expression “linevoltage” is used in accordance with its well known usage to refer toelectricity supplied by an energy source, e.g., electricity suppliedfrom a grid, including AC and DC.

In some embodiments of this type, there are provided lighting devicesthat provide lumen output of at least 600 lumens, and in someembodiments at least 750 lumens, at least 900 lumens or at least 1100lumens (or in some cases at least even higher lumen outputs)

Embodiments in accordance with the present inventive subject matter aredescribed herein in detail in order to provide exact features ofrepresentative embodiments that are within the overall scope of thepresent inventive subject matter. The present inventive subject mattershould not be understood to be limited to such detail.

Embodiments in accordance with the present inventive subject matter arealso described with reference to cross-sectional (and/or plan view)illustrations that are schematic illustrations of idealized embodimentsof the present inventive subject matter. As such, variations from theshapes of the illustrations as a result, for example, of manufacturingtechniques and/or tolerances, are to be expected. Thus, embodiments ofthe present inventive subject matter should not be construed as beinglimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing. For example, a molded region illustrated or described asa rectangle will, typically, have rounded or curved features. Thus, theregions illustrated in the figures are schematic in nature and theirshapes are not intended to illustrate the precise shape of a region of adevice and are not intended to limit the scope of the present inventivesubject matter.

The lighting devices illustrated herein are in some cases illustratedwith reference to cross-sectional drawings. These cross sections may berotated around a central axis to provide lighting devices that arecircular in nature. Alternatively, the cross sections may be replicatedto form sides of a polygon, such as a square, rectangle, pentagon,hexagon or the like, to provide a lighting device. Thus, in someembodiments, objects in a center of the cross-section may be surrounded,either completely or partially, by objects at the edges of thecross-section.

FIG. 1 is a schematic cross-sectional view of a lighting deviceaccording to the present inventive subject matter. Referring to FIG. 1,there is shown a lighting device 10 that comprises a circuit board 11, asolid state light emitter 12 on the circuit board 11 and a flame-ratedoptic 13. The optic 13 comprises snap features 14 which hold the optic13 in place relative to the circuit board 11 (which comprises six sides,each side substantially parallel to one other of the sides andsubstantially perpendicular to four other of the sides). The optic 13also can comprise one or more optical features; in this embodiment, theoptic 13 comprises a dome region 17.

Referring to FIG. 1, the solid state light emitter 12 is between aportion of the circuit board 11 and a portion of the first optic 13.When the solid state light emitter 12 is illuminated, at least a portionof light emitted by the solid state light emitter 12 passes through theoptic 13.

In this particular embodiment, the solid state light emitter 12 is apackaged LED, and the voltage drop across the solid state light emitter12 is at least 60 volts.

Referring to FIG. 1, a cavity 15 is defined between the optic 13 and thecircuit board 11. The solid state light emitter 12 is in the cavity 15.In addition, the lighting device 10 can further comprise anindex-matching element 16 in the cavity 15, between the solid statelight emitter 12 and the optic 13. In this embodiment, theindex-matching element 16 and the solid state light emitter 12 togethersubstantially fill the cavity 15.

In this embodiment, a first luminescent material 18 is dispersed withinthe optic 13.

In this embodiment, a thickness of the lighting device (in the verticaldirection in the orientation depicted in FIG. 1) is not larger thanabout 2 mm, and a width of the lighting device (in the horizontaldirection in the orientation depicted in FIG. 1) is not larger thanabout 6 mm.

FIG. 2 is a schematic bottom view of the lighting device 10, showing theregions of the bottom of the circuit board 11 that are overlapped by thesnap features 14 of the optic 13.

FIG. 3 is a schematic cross-sectional view of a lighting deviceaccording to the present inventive subject matter. Referring to FIG. 3,there is shown a lighting device 30 that comprises a circuit board 31, asolid state light emitter 32 on the circuit board 31 and a flame-ratedoptic 33. The optic 33 comprises snap features 34 which hold the optic33 in place relative to the circuit board 31. The optic 33 also cancomprise one or more optical features; in this embodiment, the optic 33comprises a dome region 37 and a roughened region 41.

In this particular embodiment, the solid state light emitter 32 is alight emitting diode chip, mounted directly on the circuit board 31(i.e., in a chip-on-board arrangement), and the voltage drop across thesolid state light emitter 32 is at least 60 volts.

A cavity 35 is defined between the optic 33 and the circuit board 31.The solid state light emitter 32 is in the cavity 35. In addition, thelighting device 30 can further comprise an index-matching element 36 inthe cavity 35.

In this embodiment, a first luminescent material 38 is dispersed withinthe index-matching element 36.

This embodiment further comprises a non-isolated power supply 39 whichsupplies electricity to the lighting device 30 through wires 40.

FIG. 4 is a schematic top view of the optic 33, showing the dome 37.FIG. 5 is a schematic top view of the solid state light emitter 32 onthe circuit board 31. From a comparison of FIGS. 4 and 5, the relativepositioning of the chip 32 and the dome 37 of the optic 33 can be seen.The spatial relationship between the chip 32 and the dome 37 depicted inFIGS. 3-5, and the respective shapes of the chip 32 and the optic 33,are representative, and persons of skill in the art can envision anenormous number of possible spatial relationships and respective shapes,all of which are within the scope of the present inventive subjectmatter.

FIG. 6 is a schematic top view of an alternative circuit board 61 onwhich five light emitting diode chips 62 are mounted (chip-on-board),and FIG. 7 is a schematic top view of an alternative optic 71 for usewith the circuit board 61 depicted in FIG. 6. FIG. 8 is a schematiccross-sectional view of the optic 71, taken along the plane 8-8 in FIG.7. As seen in FIGS. 7 and 8, the optic 71 comprises a continuous opticalfeature 72 which comprises a curved region and which extends along thelong dimension of the optic 71. The optic 71 also comprises a curvedregion 75, i.e., the optic comprises at least one curved region on eachof two opposite sides. The circuit board 61 can be received in theregion 73 defined by the optic 71, and can be held in place by snapfeatures 74 which extend along the long dimension of the optic 71 (i.e.,the snap features 74 are configured to hold the optic 71 in placerelative to a circuit board comprising six sides, each sidesubstantially parallel to one other of the sides and substantiallyperpendicular to four other of the sides, i.e., the snap features 74 arefirst and second structures configured to hold the optic 71 in placerelative to a circuit board by contacting opposite sides of the circuitboard). With the circuit board 61 received in the region 73 and with thechips 62 pointed upward (in the orientation depicted in FIG. 8), thechips 62 are directly beneath the optical feature 72. The optic 71 ismade of substantially transparent material, and so the optical feature72 is a substantially transparent region. A first dimension t₁ of theoptic 71 is not larger than about 10 mm, and a second dimension w of theoptic 71 is not larger than about 15 mm.

FIG. 9 is a schematic top view of an alternative optic 91 for use withthe circuit board 61 depicted in FIG. 6. As seen in FIG. 9, the optic 91comprises five dome regions 92. The circuit board 61 can be positionedrelative to the optic 91 such that each of the respective chips 62 isbeneath a respective one of the dome regions 92.

In embodiments in which an index-matching element is included, in anarrangement as depicted in FIG. 8, the index-matching element can fillin the space between the circuit board 61 and the optic 71 (i.e., otherthan the space occupied by the chips 62) and is in the form of acontinuous bead, whereas in an arrangement as depicted in FIG. 9, theindex-matching element can fill in each of the spaces between thecircuit board 61 and the optic 91 (i.e., other than the space occupiedby the chips 62) and is in the form of a series of globs.

FIG. 10 is a schematic top view of an alternative circuit board 101 onwhich sixteen light emitting diode chips 102 are mounted(chip-on-board), and FIG. 11 is a schematic top view of an alternativeoptic 111 for use with the circuit board 101 depicted in FIG. 10. Theoptic 111 comprises sixteen dome regions 112. The circuit board 101 canbe positioned relative to the optic 111 such that each of the respectivechips 102 is beneath one of the respective dome regions 112.

FIG. 12 is a schematic top view of an alternative circuit board 121 onwhich sixteen light emitting diode chips 122 are mounted(chip-on-board), and FIG. 13 is a schematic top view of an alternativeoptic 131 for use with the circuit board 121 depicted in FIG. 12. Theoptic 131 comprises a continuous optical feature 132. FIG. 14 is aschematic cross-sectional view of the optic 131 along plane 14-14.

FIG. 15 is a top plan view of a high voltage monolithic light emitter150 that can be employed (e.g., as the chip in the embodiment depictedin FIG. 3-5, and/or as one of the chips in the embodiments depicted inFIG. 6, 10 or 12) in some embodiments in accordance with the presentinventive subject matter. FIG. 15 depicts a solid state light emitterthat comprises a plurality of light emitting devices formed bydepositing stacked active layers on a wafer and/or substrate, and thenisolating respective regions of those stacked layers from each other toprovide a plurality of light emitting devices which are mechanicallyconnected to one another. As seen in FIG. 15, the light emitter 150includes a plurality of light emitting devices 151 on a common substrate159. The lighting emitting devices 151 are defined by isolation regions152 that define the peripheries of the individual light emitting devices151. The individual light emitting devices 151 each have an anodecontact 156 and a cathode contact 154.

As seen in FIG. 15, the anode contacts 156 of light emitting devices 151in subsequent rows are connected to the cathode contacts 154 of devices151 in previous rows by the interconnection patterns 158. The anodes 156of devices 151 in a first row of the light emitter 150 are connectedtogether to provide an anode contact 160 for the monolithic lightemitter 150. The cathode contacts 154 of the last row of devices 151 inthe array are also connected together to provide a cathode contact 162for the monolithic light emitter 150. Thus, the structure of FIG. 15provides an array of light emitting devices 151.

FIG. 16 is an exemplary cross-sectional illustration of the monolithiclight emitter 150 taken along plane 15-15. As seen in FIG. 16, multiplelight emitting devices are provided on a common substrate 159. Thesubstrate 159 may comprise any suitable material or combination ofmaterials. For example, the substrate may comprise sapphire, SiC, AlN,GaN, ZnO or other suitable semiconductor substrate. The particularmaterial for the substrate 159 may be selected based on the lightemitting devices to be formed on the substrate. Substrates andtechniques for forming light emitting devices on substrates are known tothose of skill in the art.

Furthermore, in some embodiments, the substrate 159 may be removed orthinned after forming the light emitter 150, e.g., after mounting themonolithic light emitter 150 on a circuit board.

Each light emitting device 151 depicted in FIG. 16 also includes ann-type semiconductor layer 164 that may act as a contact layer, one ormore quantum well layers 166 and a p-type semiconductor layer 168 thatalso may act as a contact layer. These layers are collectively referredto as the active layers of the device.

The individual devices 151 of the lighting device 150 are defined byisolation regions 152. The isolation regions 152 may, in someembodiments, be provided by ion implantation to create insulating orsemi-insulating regions that extend through the active layers asillustrated in FIG. 16. Alternatively or additionally, trenches could beformed between the devices 151. The trenches could, optionally, befilled with an insulator, such as SiO_(x) or SiN, to provide a moreplanar surface on which the electrical interconnect 158 is provided.Combinations of trenches and implantation could also be provided. Forexample, a trench could be formed and then ions implanted into thesidewalls and/or bottom of the trench to make these regions insulatingor semi-insulating.

Also illustrated in FIG. 16 is an n⁺ contact region 169 that extendsfrom a top surface of the device through the isolating region 152 to then-type layer 164. The n⁺ contact region 169 allows for the formation ofthe cathode contact 154 to provide a more planar device. The contactregion 169 may, for example, be provided by ion implantation through theisolation region to the n-type layer 164. An n-type contact 154 providesa cathode contact for each device and a p-type contact 156 provides ananode contact for each device.

FIG. 16 also illustrates an optional insulating layer 163 that may beprovided on exposed portions of the devices and/or between devices. Theinsulating layer 163 may function as a protective and/or passivationlayer for the devices.

FIG. 17 is a schematic top view of an alternative optic 171 for use withthe circuit board 61 depicted in FIG. 6. FIG. 18 is a schematiccross-sectional view of the optic 171, taken along the plane 18-18 inFIG. 17. As seen in FIGS. 17 and 18, the optic 171 comprises acontinuous optical feature 172 extending along the long dimension of theoptic 171. The circuit board 61 can be received in the region 173defined by the optic 171, and can be held in place by snap features 174which extend along the long dimension of the optic 171. With the circuitboard 61 received in the region 173 and with the chips 62 pointed upward(in the orientation depicted in FIG. 18), the chips 62 are directlybeneath the optical feature 172. The optical feature 172 can beconfigured to provide any suitable optical property, e.g., in theembodiment depicted in FIG. 18, the optical feature 172 provides asidelooker feature for a solid state light emitter on a circuit boardpositioned within the region 173.

FIG. 19 is a top plan view of a high voltage light emitter 190 that canbe employed (e.g., as the chip in the embodiment depicted in FIG. 3-5,and/or as one of the chips in the embodiments depicted in FIG. 6, 10 or12) in some embodiments in accordance with the present inventive subjectmatter. FIG. 19 depicts a solid state light emitter 190 that comprises aplurality of light emitting diode chips 191 arranged in series on afirst region 192 of a circuit board 193. In some embodiments, the firstregion can have a surface area of not larger than about 2.0 squaremillimeters.

FIG. 20 is a schematic sectional view of a lamp 200 that comprises acircuit board 201, a solid state light emitter 202 on the circuit board201, an optic 203, a housing 204 and a diffuser 205. In this embodiment,the housing 204 comprises a plurality of heat dissipation fins 206, andcan be formed of any suitable material, e.g., aluminum.

FIG. 21 is a schematic perspective view of a lamp 210 in the form of alinear troffer, comprising a lighting device 211 (which comprises acircuit board with ten light emitting diode chips mounted thereon in aline, and a corresponding optic) and a reflective housing 212.

Furthermore, while certain embodiments of the present inventive subjectmatter have been illustrated with reference to specific combinations ofelements, various other combinations may also be provided withoutdeparting from the teachings of the present inventive subject matter.Thus, the present inventive subject matter should not be construed asbeing limited to the particular exemplary embodiments described hereinand illustrated in the Figures, but may also encompass combinations ofelements of the various illustrated embodiments.

Many alterations and modifications may be made by those having ordinaryskill in the art, given the benefit of the present disclosure, withoutdeparting from the spirit and scope of the inventive subject matter.Therefore, it must be understood that the illustrated embodiments havebeen set forth only for the purposes of example, and that it should notbe taken as limiting the inventive subject matter as defined by thefollowing claims. The following claims are, therefore, to be read toinclude not only the combination of elements which are literally setforth but all equivalent elements for performing substantially the samefunction in substantially the same way to obtain substantially the sameresult. The claims are thus to be understood to include what isspecifically illustrated and described above, what is conceptuallyequivalent, and also what incorporates the essential idea of theinventive subject matter.

Any two or more structural parts of the lighting devices describedherein can be integrated. Any structural part of the lighting devicesdescribed herein can be provided in two or more parts (which may be heldtogether in any known way, e.g., with adhesive, screws, bolts, rivets,staples, etc.).

1. A lighting device, comprising: at least a first circuit board; atleast a first solid state light emitter on the first circuit board; andat least a first optic held in place relative to the first circuitboard, at least part of the first solid state light emitter between atleast a portion of the first circuit board and at least a portion of thefirst optic, if the first solid state light emitter is illuminated, atleast a portion of light emitted by the first solid state light emitterpasses through the first optic, and a voltage drop across the firstsolid state light emitter is at least 60 volts.
 2. A lighting device asrecited in claim 1, wherein the lighting device further comprises atleast a first index-matching element between at least a portion of thefirst solid state light emitter and the first optic.
 3. A lightingdevice as recited in claim 2, wherein the index-matching elementcomprises at least a first luminescent material.
 4. A lighting device asrecited in claim 1, wherein the first optic comprises at least a firstluminescent material.
 5. A lighting device as recited in claim 1,wherein the first optic is flame-rated.
 6. A lighting device as recitedin claim 1, wherein the first optic is in direct contact with the firstcircuit board.
 7. A lighting device as recited in claim 1, wherein thefirst solid state light emitter is an LED.
 8. A lighting device asrecited in claim 1, wherein the first solid state light emitter is alight emitting diode chip in direct contact with the first circuitboard.
 9. A lighting device as recited in claim 1, wherein the firstsolid state light emitter comprises a plurality of light emittingdevices formed by depositing stacked active layers on a wafer and/orsubstrate, and then isolating respective regions of those stacked layersfrom each other to provide a plurality of light emitting devices whichare mechanically connected to one another.
 10. A lighting device asrecited in claim 1, wherein the first solid state light emittercomprises a plurality of light emitting diode chips arranged in serieson a first region of the first circuit board, the first region having asurface area of not larger than about 2.0 square millimeters.
 11. Alighting device as recited in claim 1, wherein at least a firstdimension of the lighting device is not larger than about 10 mm.
 12. Alighting device as recited in claim 11, wherein at least a seconddimension of the lighting device is not larger than about 15 mm.
 13. Alighting device as recited in claim 1, wherein the lighting devicefurther comprises at least a first power supply.
 14. A lighting deviceas recited in claim 13, wherein the first power supply is non-isolated.15. A lighting device, comprising: at least a first circuit board; atleast a first solid state light emitter on the first circuit board; atleast a first optic held in place relative to the first circuit board;and at least a first non-isolated power supply configured to supplypower to illuminate the first solid state light emitter; at least partof the first solid state light emitter between at least a portion of thefirst circuit board and at least a portion of the first optic, and ifthe first solid state light emitter is illuminated, at least a portionof light emitted by the first solid state light emitter passes throughthe first optic.
 16. A lighting device as recited in claim 15, whereinthe lighting device further comprises at least a first index-matchingelement between at least a portion of the first solid state lightemitter and the first optic.
 17. A lighting device as recited in claim16, wherein the index-matching element comprises at least a firstluminescent material.
 18. A lighting device as recited in claim 15,wherein the first optic comprises at least a first luminescent material.19. A lighting device as recited in claim 15, wherein the first optic isflame-rated.
 20. A lighting device as recited in claim 15, wherein thefirst optic is in direct contact with the first circuit board.
 21. Alighting device as recited in claim 15, wherein the first solid statelight emitter is an LED.
 22. A lighting device as recited in claim 15,wherein the first solid state light emitter is a light emitting diodechip in direct contact with the first circuit board.
 23. A lightingdevice as recited in claim 15, wherein the first solid state lightemitter comprises a plurality of light emitting devices formed bydepositing stacked active layers on a wafer and/or substrate, and thenisolating respective regions of those stacked layers from each other toprovide a plurality of light emitting devices which are mechanicallyconnected to one another.
 24. A lighting device as recited in claim 15,wherein the first solid state light emitter comprises a plurality oflight emitting diode chips arranged in series on a first region of thefirst circuit board, the first region having a surface area of notlarger than about 2.0 square millimeters.
 25. A lighting device asrecited in claim 15, wherein at least a first dimension of the lightingdevice is not larger than about 10 mm.
 26. A lighting device as recitedin claim 25, wherein at least a second dimension of the lighting deviceis not larger than about 15 mm.
 27. A lighting device, comprising: atleast a first circuit board; at least a first solid state light emitteron the first circuit board; and at least a first optic held in placerelative to the first circuit board, at least part of the first solidstate light emitter between at least a portion of the first circuitboard and at least a portion of the first optic, if the first solidstate light emitter is illuminated, at least a portion of light emittedby the first solid state light emitter passes through the first optic,and the first optic is flame-rated.
 28. A lighting device as recited inclaim 27, wherein the lighting device further comprises at least a firstindex-matching element between at least a portion of the first solidstate light emitter and the first optic.
 29. A lighting device asrecited in claim 28, wherein the index-matching element comprises atleast a first luminescent material.
 30. A lighting device as recited inclaim 27, wherein the first optic comprises at least a first luminescentmaterial.
 31. A lighting device as recited in claim 27, wherein thefirst solid state light emitter is an LED.
 32. A lighting device asrecited in claim 27, wherein the first solid state light emitter is alight emitting diode chip in direct contact with the first circuitboard.
 33. A lighting device as recited in claim 27, wherein the firstsolid state light emitter comprises a plurality of light emittingdevices formed by depositing stacked active layers on a wafer and/orsubstrate, and then isolating respective regions of those stacked layersfrom each other to provide a plurality of light emitting devices whichare mechanically connected to one another.
 34. A lighting device asrecited in claim 27, wherein the first solid state light emittercomprises a plurality of light emitting diode chips arranged in serieson a first region of the first circuit board, the first region having asurface area of not larger than about 2.0 square millimeters.
 35. Alighting device as recited in claim 27, wherein at least a firstdimension of the lighting device is not larger than about 10 mm.
 36. Alighting device as recited in claim 35, wherein at least a seconddimension of the lighting device is not larger than about 15 mm.
 37. Alighting device as recited in claim 27, wherein the lighting devicefurther comprises at least a first power supply.
 38. A lighting deviceas recited in claim 37, wherein the first power supply is non-isolated.39. A lighting device as recited in claim 27, wherein the first optic isin direct contact with the first circuit board.
 40. An optic,comprising: at least a first translucent region, at least a firstdimension of the optic not larger than about 10 mm, at least a seconddimension of the optic not larger than 15 mm.
 41. An optic as recited inclaim 40, wherein the optic is flame-rated.
 42. An optic as recited inclaim 40, wherein the optic comprises at least one structure configuredto hold the optic in place relative to a circuit board comprising sixsides, each side substantially parallel to one other of the sides andsubstantially perpendicular to four other of the sides.
 43. An optic asrecited in claim 40, wherein the optic comprises at least first andsecond structures configured to hold the optic in place relative to acircuit board by contacting opposite sides of the circuit board.
 44. Anoptic as recited in claim 40, wherein the optic comprises at least onecurved region.
 45. An optic as recited in claim 40, wherein the opticcomprises at least one curved region on each of two opposite sides. 46.An optic as recited in claim 40, wherein the first optic comprises atleast a first luminescent material.
 47. A lighting device as recited inclaim 40, wherein the first dimension of the lighting device is notlarger than about 2 mm.
 48. A lighting device as recited in claim 40,wherein the first dimension of the lighting device is not larger thanabout 4 mm.
 49. A lighting device as recited in claim 40, wherein thefirst dimension of the lighting device is not larger than about 6 mm.50. A lighting device as recited in claim 40, wherein the firstdimension of the lighting device is not larger than about 8 mm.
 51. Alighting device as recited in claim 40, wherein at least a seconddimension of the lighting device is not larger than about 6 mm.
 52. Alighting device as recited in claim 40, wherein at least a seconddimension of the lighting device is not larger than about 8 mm.
 53. Alighting device as recited in claim 40, wherein at least a seconddimension of the lighting device is not larger than about 10 mm.
 54. Anoptic, comprising: at least a first translucent region, at least onestructure configured to hold the optic in place relative to a circuitboard, the optic flame-rated.
 55. An optic as recited in claim 54,wherein the at least one structure configured to hold the optic in placerelative to a circuit board comprises at least one structure configuredto hold the optic in place relative to a circuit board comprising sixsides, each side substantially parallel to one other of the sides andsubstantially perpendicular to four other of the sides.
 56. An optic asrecited in claim 54, wherein the at least one structure configured tohold the optic in place relative to a circuit board optic comprises atleast first and second structures configured to hold the optic in placerelative to a circuit board by contacting opposite sides of the circuitboard.
 57. An optic as recited in claim 54, wherein the optic comprisesat least one curved region.
 58. An optic as recited in claim 54, whereinthe optic comprises at least one curved region on each of two oppositesides.
 59. An optic as recited in claim 54, wherein the first opticcomprises at least a first luminescent material.
 60. A method of makinga lighting device, comprising: bringing at least a first structure of afirst optic into contact with a first circuit board, the first structureconfigured to hold the first optic in place relative to the firstcircuit board, at least a first solid state light emitter on the firstcircuit board, so that: at least part of the first solid state lightemitter is between at least a portion of the first circuit board and atleast a portion of the first optic, and if the first solid state lightemitter is illuminated, at least a portion of light emitted by the firstsolid state light emitter passes through the first optic.
 61. A methodas recited in claim 60, wherein a voltage drop across the first solidstate light emitter is at least 60 volts.
 62. A method as recited inclaim 60, wherein the method further comprises placing at least a firstindex-matching element so that the first index-matching element isbetween at least a portion of the first solid state light emitter andthe first optic.
 63. A method as recited in claim 60, wherein the firstoptic is flame-rated.
 64. A method as recited in claim 60, wherein thefirst solid state light emitter is an LED.
 65. A method as recited inclaim 60, wherein the first solid state light emitter is a lightemitting diode chip in direct contact with the first circuit board. 66.A method as recited in claim 60, wherein the first solid state lightemitter comprises a plurality of light emitting devices formed bydepositing stacked active layers on a wafer and/or substrate, and thenisolating respective regions of those stacked layers from each other toprovide a plurality of light emitting devices which are mechanicallyconnected to one another.
 67. A method as recited in claim 60, whereinthe first solid state light emitter comprises a plurality of lightemitting diode chips arranged in series on a first region of the firstcircuit board, the first region having a surface area of not larger thanabout 2.0 square millimeters.
 68. A method as recited in claim 60,wherein at least a first dimension of the optic is not larger than about10 mm.
 69. A method as recited in claim 60, wherein at least a seconddimension of the optic is not larger than about 15 mm.
 70. A method asrecited in claim 60, wherein the method further comprises electricallyconnecting at least a first power supply to the first circuit board. 71.A method as recited in claim 70, wherein the first power supply isnon-isolated.